import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.util.LinkedList;
import java.util.List;

public class Hakbat_Sul {
	static int Players=5,Rank=TheRank(Players),Games=TheGames(Players),t=0,row,column,numofgames;
	static double firstodd,secondodd,Total;
	static double TheMainBoard[][]=new double [Rank][Games+1];
	static double TheMultyBoard[][]=new double [Rank][Games];
	static double TheFinalBoard[]=new double [Games+1];
	static String TheGameBoard[]=new String [Games];
	static String TheRankBoard[][]=new String [Rank][Players];
	static int ThePlayerboard[]= new int[Players];
	static int TheRankingBoard[][]= new int [Players][Players];
	static double TheODDBoard[][]= new double [Rank][Games];
	static String TheFirstRank[]=new String [Players];




	public static void main(String[] args) {
		readFromFile();

		row=0;
		column=0;
		Total=0;
		FillPlayers();
		ranks();
		MakeGameBoard();
		MakeRank();
		MakingTheOddTable();
		TheLastTable();
		Solve();
		System.out.print(TheFinalBoard[Players]);
	}


	private static void readFromFile(){
		try(BufferedReader br = new BufferedReader(new FileReader("input.txt"))) {
			StringBuilder sb = new StringBuilder();
			String line = br.readLine();
			List<String> Result=new LinkedList<String>(); //intialize List of Strings
			Result.add(line); //add First Line (String) to the List
			while (line != null) {
				sb.append(line);
				sb.append(System.lineSeparator());
				line = br.readLine();
				Result.add(line);
			}
			String[] array = Result.toArray(new String[Result.size()]);
			setValuesFrom(array);
		}
		catch (IOException e) {
			e.printStackTrace();
		}
	}
	private static void setValuesFrom(String[] File){

		for (int i=0;i<File.length;i++){
			switch (File[i].charAt(0)){
			case 'n':
				String re=File[i].substring(2);
				Players=Integer.valueOf(re);
				break;

			case 'k':
				String res=File[i].substring(2);
				numofgames=Integer.valueOf(res);
				break;

			case 'R':
				i=i+2;
				for (int j=0;j<Players;j++){ //Adding Ranking - index 0 is first place
					TheFirstRank[j]=File[i];
					i=i+1;
				}
			case 'B':
				i=i+1;
				int c=Players-1;
				while (c>=0){
					if (!Character.isDigit(File[i].charAt(0)))
						i++;
					else {
						for (int r=0;r<TheRankingBoard.length;r++){
							TheRankingBoard[r][c]=Integer.valueOf(File[i]); // transfering string to int
							i=i+1;
						}
						c--; // going one column to the left
					}
				}
				break;
			}
		}
	}
	private static void FillPlayers(){
		for (int i=0;i<Players;i++)
			ThePlayerboard[i]=i+1;

	}
	public static void TheLastTable(){
		double max =0;
		for(row=0;row<Rank;row++){
			for(column=0;column<Games;column++){
				if(TheMainBoard[row][column]>max) max = TheMainBoard[row][column];

			}
			TheMainBoard[row][Players]=max;
			max=0;
		}

	}




	public static void Solve(){
		numofgames=numofgames-1;
		while(numofgames!=1 ){
			for (row=0;row<Rank;row++){
				for (column=0;column<Games;column++){
					Total=TheMultyBoard[row][column];
					Total=Total+(TheODDBoard[row][column]*Win(TheRankBoard[row],TheGameBoard[column]))+((1-TheODDBoard[row][column])*Lost(TheRankBoard[row],TheGameBoard[column]));
					TheMainBoard[row][column]=Total;
				}

			}
			TheLastTable();
			numofgames=numofgames-1;
		}
		if(numofgames==1){
			int count =0;
			int rows =0;

			for(int j=0;j<Rank;j++){
				for(int k=0;k<Players;k++){
					if(TheFirstRank[k].equals(TheRankBoard[j][k])) count++;
					if(count==Players) rows=j;
					if(rows!=0) break;
				}
				if(rows!=0) break;
				count=0;
			}




			for (column=0;column<Games;column++){
				Total=TheMultyBoard[rows][column];
				Total=Total+(TheODDBoard[rows][column]*Win(TheRankBoard[rows],TheGameBoard[column]))+((1-TheODDBoard[rows][column])*Lost(TheRankBoard[rows],TheGameBoard[column]));
				TheFinalBoard[column]=Total;
			}


			TheFinal();


		}
	}
	private static void TheFinal() {

		double max =0;
		for(int i=0;i<Games;i++){
			if(TheFinalBoard[i]>max) max = TheFinalBoard[i];

		}
		TheFinalBoard[Players]=max;
		max=0;
	}
	public static double Win(String X[],String Y) {
		int count =0,rows=0;
		String Z[]=new String[X.length];

		for(int l=0;l<X.length;l++){
			Z[l]=X[l];
		}

		char winner = Y.charAt(0);
		char looser = Y.charAt(1);
		String temp;
		int i=0;
		int winnerplace=0,looserplace=0;
		while (i<Players){
			if(winner==Z[i].charAt(0)) winnerplace=i;
			if(looser==Z[i].charAt(0)) looserplace=i;
			i++;
		}


		for(int j=0;j<Rank;j++){
			for(int k=0;k<Players;k++){
				if(Z[k].equals(TheRankBoard[j][k])) count++;
				if(count==Players) rows=j;
				if(rows!=0) break;
			}
			if(rows!=0) break;
			count=0;
		}

		if(winnerplace<looserplace) return TheMainBoard[rows][Players];
		else{
			temp =Z[winnerplace];
			Z[winnerplace]=Z[looserplace];
			Z[looserplace]=temp;
			if(TheRankBoard[0][0]!=null);
			count=0;
			rows=0;
			for(int j=0;j<Rank;j++){
				for(int k=0;k<Players;k++){
					if(Z[k].equals(TheRankBoard[j][k])) count++;
					if(count==Players) rows=j;
					if(rows!=0) break;
				}
				if(rows!=0) break;
				count=0;
			}
			double x=TheMainBoard[rows][Players];
			return x;



		}

	}
	public static double Lost(String[] X,String Y) {

		String Z[]=new String[X.length];

		for(int l=0;l<X.length;l++){
			Z[l]=X[l];
		}

		char winner = Y.charAt(1);
		char looser = Y.charAt(0);
		String temp;
		int i=0,rows=0,count=0;
		int winnerplace=0,looserplace=0;
		while (i<Players){
			if(winner==Z[i].charAt(0)) winnerplace=i;
			if(looser==Z[i].charAt(0)) looserplace=i;
			i++;
		}

		for(int j=0;j<Rank;j++){
			for(int k=0;k<Players;k++){
				if(Z[k].equals(TheRankBoard[j][k])) count++;
				if(count==Players) rows=j;
				if(rows!=0) break;
			}
			if(rows!=0) break;
			count=0;
		}




		if(winnerplace<looserplace) return TheMainBoard[rows][Players];
		else{
			temp =Z[winnerplace];
			Z[winnerplace]=Z[looserplace];
			Z[looserplace]=temp;
			if(TheRankBoard[0][0]!=null);
			count=0;
			rows=0;
			for(int j=0;j<Rank;j++){
				for(int k=0;k<Players;k++){
					if(Z[k].equals(TheRankBoard[j][k])) count++;
					if(count==Players) rows=j;
					if(rows!=0) break;
				}
				if(rows!=0) break;
				count=0;
			}

			return TheMainBoard[rows][Players];



		}



	}




	public static int TheRank(int n){//עצרת כדי למצוא את גודל המערך
		if (n==0 || n==1)
			return 1;

		return n*TheRank(n-1);}
	public static int TheGames(int Games1){// כדי למצוא את גודל מערך של המשחקים
		int Games2=(TheRank(Games1)/(TheRank(Games1-2)*TheRank(2)));

		return Games2;
	}
	public static void ranks(){
		for (int i=0;i<Rank;i++)
			for (int j=0;j<Players;j++) TheRankBoard[i][j]="";


	}
	public static void MakeGameBoard(){

		for (int i=1;i<Players;i++){
			ThePlayerboard[i-1]=i;
		}
		int i=0;


		for(int Firstplayer=1;Firstplayer<=Players;Firstplayer++){
			for (int second=2;second<=Players;second++){
				if (Firstplayer<second){
					String game=""+Firstplayer+""+second;
					TheGameBoard[i]=game;
					i++;

				}
			}
		}


	}




	public static void MakeRank(){

		Hakbat_Sul p=new Hakbat_Sul();
		p.permute(ThePlayerboard, 0);}
	public void printArray(int []a) {
		for (int i = 0; i<a.length; i++) {
			TheRankBoard[t][i]=""+a[i];
		}

		t++;
	}
	public void permute(int []a,int k ) {
		if(k==a.length)
			printArray(a);
		else
			for (int i = k; i <a.length; i++) {
				int temp=a[k];
				a[k]=a[i];
				a[i]=temp;
				permute(a,k+1);
				temp=a[k];
				a[k]=a[i];
				a[i]=temp;}

	}




	public static void MakingTheOddTable(){
		for (int i=0;i<Rank;i++){
			for (int j=0;j<Games;j++){

				char first=TheFirst(TheGameBoard[j]);
				int FirstRank =CheckWhatPlace(first,i);

				char second=TheSecond(TheGameBoard[j]);
				int SecondRank =CheckWhatPlace(second,i);

				double odd=TheOdd(first,FirstRank,second,SecondRank);
				TheMultyBoard[i][j]=(int) (firstodd*secondodd);
				TheMainBoard [i][j]=(int) (firstodd*secondodd);
				TheODDBoard[i][j]=odd;
			}
		}


	}
	public static double TheOdd(char firstplace ,int FirstRating ,char secondplace, int SecondRating){

		int first=(int)firstplace-48;
		int second=(int)secondplace-48;


		firstodd=TheRankingBoard[FirstRating-1][first-1];
		secondodd=TheRankingBoard[SecondRating-1][second-1];

		double thesum=firstodd-secondodd;

		if(thesum<0){
			thesum=thesum*-1;
			double TheODD=1/(2+(thesum));
			return TheODD;
		}

		double TheODD=1/(2+(thesum));
		return 1-TheODD;
	}
	static int CheckWhatPlace(char f,int row) {
		int place=0;
		int i=0;
		for (i=0;i<Players;i++){
			if(f==TheRankBoard[row][i].charAt(0)) place=i+1;

		}
		return place;
	}
	public static char TheFirst(String game){
		char Thefirst=game.charAt(0);
		return Thefirst;
	}
	public static char TheSecond(String game){
		char TheSec=game.charAt(1);
		return TheSec;
	}


}